2004

6.8

1998

6.0

1985

6.0

2003

6.2

1997

5.5

1979

6.1

2004

4.2

2008

4.3

2001

6.5

1981

5.5

1992

5.5

1986

5.8

1977

6.5

1985

5.3

1996

5.2

1996

4.1

1965

5.1

1987

5.8

1967

6.1

1991

6.0